Electronic Supplementary Material (ESI) for rganic & Biomolecular Chemistry. This journal is The Royal Society of Chemistry 2015 Supporting Information Radical fluorination powered expedient synthesis of 3 fluorobicyclo[1.1.1]pentan 1 amine Yi Ling Goh and Vikrant A. Adsool* Institute of Chemical and Engineering Sciences (ICES), Agency for Science, Technology, and Research (A*STAR) 8 Biomedical Grove, Neuros Building, # 07 01, Singapore 138665 (Singapore) *vikrant_adsool@ices.a star.edu.sg Table of contents General Information Materials S2 Instrumentation S2 Experimental Procedures General procedure for the decarboxylative fluorination of bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (3) to 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (4) S3 Scale up synthesis of 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3) S4 Procedure of bicyclo[1.1.1]pentane derivatives S5 1 H NMR, 13 C NMR, 19 F NMR spectra, Single X ray crystal structures S9 S1
General Information Materials. All chemicals were purchased from Sigma Aldrich, Alfa Aesar and Merck were used as received. Anhydrous t BuH was taken from Sure/Seal bottle (Sigma Aldrich). Deionised water was degassed with the sonicator followed by bubbling nitrogen. All reactions requiring anhydrous conditions were carried out under argon atmosphere using oven dried glassware unless otherwise stated. Reaction progress was monitored using Merck 60 F254, 0.25 μm silica gel plates (TLC plates) and spots were visualized by UV and/or potassium permanganate, or ceric ammonium molybdate stain, and/or ninhydrin stain. Flash column chromatography was carried out using Merck 60 F254, 0.040 0.063 μm silica gel. Preparative TLC chromatography was carried out using Merck 60 F254, 0.25 μm silica gel plates. Names of structures were generated using ChemBioDraw ultra 14.0.0. Instrumentation. Proton nuclear magnetic resonance ( 1 H NMR) spectra, carbon nuclear magnetic resonance ( 13 C NMR) and fluorine ( 19 F NMR) spectra were recorded on Bruker 400 MHz with CryoProbe. Chemical shifts for protons were reported in parts per million (ppm) that are referenced to residual protium in the NMR solvent (CDCl 3 : 7.26 ppm; CD 3 D: 3.31 ppm). Chemical shifts for carbon were reported in ppm referenced to the carbon resonances of the NMR solvent (CDCl 3 : 77.16 ppm; CD 3 D: 49.0 ppm). NMR Spectra were processed using MestReNova 10.0.1. Data is presented as follows: chemical shift, multiplicity (s = singlet, d = doublet), integration and coupling constants (J) in Hertz (Hz). Electron impact mass spectra (EIMS) were measured using a Finnigan MAT95XP double focusing mass spectrometer. High resolution electrospray ionization (HRMS ESI) mass spectra were recorded using Agilent 6210 Time of Flight LC/MS. Infrared (IR) spectra were measured on a PerkinElmer Spectrum100 FT IR spectrophotometer. Differential scanning calorimetry and melting point (uncorrected) were measured on Mettler Toledo DSC 1 and the data processed using STARe Default DB V10.00 software. Melting point (uncorrected) was also measured by BÜCHI B 540. S2
Experimental Procedures General procedure for the optimization studies of decarboxylative fluorination of bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) to 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3). To a RBF containing bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4)* (100 mg, 0.425 mmol) was added AgN 3 (5, 7.5, 10 or 20 mol%) and SELECTFLUR (1.3, 1.8 or 2.5 eq.), was thoroughly flushed with argon under a condenser. To this mixture was added deoxygenated water (3.2 ml, 0.2 M) and stirred at 50, 65 or 90 C for 16 h. The reaction was allowed to cool to rt and extracted with diethyl ether. This ether extract was dried over sodium sulphate, filtered and evaporated to dryness. This solid was re dissolved in pentane and filtered slowly. The filtrate was concentrated in vacuo to afford 3 as a white solid. To recover starting material 4 (if any), the remaining residue above was washed with DCM, dissolved with diethyl ether and filtered. The ether filtrate was concentrated in vacuo to recover 4 as a pale yellow solid. *The bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) was obtained from TCG Lifesciences (~$150/gram). Table 1 ptimization studies for the decarboxylative fluorination of bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) to 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3). Entry AgN 3 (mol%) SELECTFLUR (eq.) Temp ( C) 3 (%) Recovered 4 (%) 1 10 1.8 65 50% ~2% 2 10 1.8 90 47% 0% 3 10 1.8 50 56% 4% 4 10 1.3 65 49% 18% 5 20 1.8 65 50% 4% 6 10 2.5 65 63% 4% 7 7.5 2.5 65 67% 8% 8 5 a 2.5 65 50% a 27% a Inconsistent yields were observed when AgN 3 is 5 mol% or lower. S3
Scale up of bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) to 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3). To a RBF containing bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) (3.0 g, 19.2 mmol) was added AgN 3 (245 mg, 1.44 mmol, 7.5 mol%) and SELECTFLUR (17.02 g, 48.0 mmol, 2.5 eq.), was thoroughly flushed with argon under a condenser. To this mixture was added deoxygenated water (96 ml) and stirred at 65 C for 16 h. The reaction was allowed to cool to rt and extracted with diethyl ether. This ether extract was dried over sodium sulphate, filtered and evaporated to dryness. This solid was re dissolved in pentane and filtered slowly. The filtrate was concentrated in vacuo to afford 3 (1.62 g, 65%) as a white solid. The remaining residue above was washed with DCM, dissolved with diethyl ether and filtered. The ether filtrate was concentrated in vacuo to recover 4 (271 mg, 9%) as a pale yellow solid. 1 H NMR (400 MHz, CDCl 3 ) δ 2.40 (d, J (H,F) = 2.4 Hz, 6H). 13 C NMR (101 MHz, CDCl 3 ) δ 174.5 (d, J (C,F) = 36.7 Hz), 74.8 (d, J (C,F) = 328.9 Hz), 55.7 (d, J (C,F) = 22.1 Hz), 28.1 (d, J (C,F) = 47.9 Hz). 19 F NMR (376 MHz, CDCl 3 ) δ 149.8. HRMS: (ESI TF) m/z: [M H] Calcd for C 6 H 6 F 2 m/z 129.0357; Found 129.0352. IR: 2933.5, 1686.9, 1521.5, 1430.7, 1325.8, 1260.0, 1219.0, 1055.4, 945.1, 747.6, 614.2 cm 1. Differential scanning calorimetry (DSC): thermal potential of 699 J/g with an onset temperature of 203 C. mp: 123 C. Single X ray crystal: slow evaporation of 4 in pentane in the refrigerator. Table 2 Scale up studies for the decarboxylative fluorination of bicyclo[1.1.1]pentane 1,3 dicarboxylic acid (4) to 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3). Entry SM AgN3 (mol %) SELECTFLUR (eq.) 4 (%) Recovered 3 (%) 1 0.5 g 7.5 1.8 59% 8% 2 1 g 7.5 2.5 68% 2% 3 1 g 5 2.5 43% 28% 4 1 g 10 2.5 63% 0% 5 3 g 7.5 2.5 65% 9% 6 3 g 10 2.5 64% 0% S4
3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3) from 3 (methoxycarbonyl)bicyclo[1.1.1]pentane 1 carboxylic acid (8). To a RBF containing 3 (methoxycarbonyl)bicyclo[1.1.1]pentane 1 carboxylic acid (8) (100 mg; 0.588 mmol) was added AgN 3 (20.0 mg, 0.188 mmol, 20 mol%) and SELECTFLUR (416 mg, 1.18 mmol, 2 eq), was thoroughly flushed with argon under a condenser. To this mixture was added deoxygenated water (2.9 ml) and stirred at 65 C for 16 h. The reaction was allowed to cool to rt and extracted with diethyl ether. To this ether extract was added NaH (42.3 mg, 1.058 mmol, 1.8 eq.) dissolved in 3:1 THF:H 2 (2.9 ml), forming a biphasic reaction mixture. This mixture was stirred at 50 C for 16 h. The reaction was allowed to cool to rt, and the organic layer separated. The aqueous layer was acidified with 2 N HCl and extracted with diethyl ether, dried over sodium sulphate, filtered and evaporated to dryness. This solid was re dissolved in pentane and filtered slowly. The filtrate was concentrated in vacuo to afford 3 (24.3 mg, 32%) as a white solid. tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13) and 1,3 bis(3 fluorobicyclo[1.1.1]pentan 1 yl)urea (14). To a dried 2 necked RBF (heatgun dried under vacuum) was added 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3) (2.33 g, 17.9 mmol), was thoroughly flushed with argon under a condenser. Anhydrous t BuH (24 ml) followed by Et 3 N (2.62 ml, 18.8 mmol, 1.05 eq.) were added. DPPA (3.93 ml, 18.3 mmol, 1.02 eq.) was added dropwise into the reaction mixture within 15 min and stirred at rt for 2 h, followed by refluxing for another 3 h. The reaction mixture was evaporated under reduced pressure and diluted with diethyl ether. This ether extract was washed with saturated bicarbonate, dried over sodium sulphate, filtered and concentrated in vacuo. The residue was purified by silica gel flash chromatography (gradient elution from 0:100 to 100:0 with product 13 eluting from 10:90 to 15:85 and urea side product 14 eluting from 70:30 to 90:10 diethyl ether pentane) to afford 13 (3.0 g, 83%) as a white solid. The isolated urea side product was further purified by trituration with diethyl ether:dcm mixture (10:0.5) to afford 14 (52 mg, 2.6%) a white solid. Note: 13 can also be carried to the next step without purification by eluting the reaction mixture through a short pad of silica with 20% diethyl ether in pentane. S5
13: 1 H NMR (400 MHz, CDCl 3 ) δ 2.32 (br d, J (H,F) = 1.8 Hz, 6H)*, 1.45 (s, 9H). 1 H NMR (400 MHz, CD 3 D) δ 2.25 (d, J (H,F) = 2.1 Hz, 6H), 1.44 (s, 9H). 13 C NMR (101 MHz, CDCl 3 ) δ 154.9, 80.3, 76.9 (d, J (C,F) = 315.6 Hz), 55.4 (d, J (C,F) = 20.4 Hz), 40.0 (d, J (C,F) = 71.5 Hz), 28.5. 13 C NMR (101 MHz, CD 3 D) δ 157.4, 80.5, 77.8 (d, J (C,F) = 314.3 Hz), 55.8 (d, J (C,F) = 20.3 Hz), 40.4 (d, J (C,F) = 70.6 Hz), 28.7. 19 F NMR (376 MHz, CDCl 3 ) δ 169.1. IR: 3347.3, 2996.1, 1688.7, 1508.0, 1252.2, 1164.5, 1017.8, 613.5 cm 1. DSC: thermal potential of 431 J/g with an onset temperature of 233 C. mp : 137 C. Single X ray crystal: slow evaporation of 13 in pentane at rt. *Doublet is a broad peak. Depending on the concentration, coupling constant could range from 1.7 to 2.1 ppm. 14: 1 H NMR (400 MHz, CD 3 D) δ 2.27 (d, J (H, F) = 2.1 Hz, 6H). 13 C NMR (101 MHz, CD 3 D) δ159.5, 77.7 (d, J (C, F) = 314.4 Hz), 56.0 (d, J (C, F) = 20.3 Hz), 40.6 (d, J (C, F) = 70.9 Hz). 19 F NMR (376 MHz, CD 3 D) δ 169.9. HRMS: (ESI TF) m/z: [M+H] + Calcd for C 11 H 15 F 2 N 2 m/z 229.1147; Found 229.1145. (ESI TF) m/z: [M+Na] + Calcd for C 11 H 14 F 2 N 2 Na m/z 251.0966 ; Found 251.0963. IR: 3550.1, 3016.1, 1641.2, 1562.3, 1244.8, 1086.9, 588.2 cm 1. DSC: thermal potential of 1777 J/g with an onset temperature of 247 C. mp: 235 238 C (decomposition). Single X ray crystal: Layering technique with 14 dissolved in DCM layered with diethyl ether on top. 3 fluorobicyclo[1.1.1]pentan 1 aminium chloride (2.HCl). To tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13) (3.0 g, 14.9 mmol) was added 4 N HCl in dioxane (37 ml, 149 mmol, 10 eq.) and stirred overnight at rt. Reaction mixture was then evaporated to dryness to furnish the crude product as a pale yellow solid. This residue was then washed with diethyl ether followed by DCM, to afford 2.HCl (1.97 g, 96%) as a white solid. 1 H NMR (400 MHz, CD 3 D) δ 2.43 (d, J (H,F) = 2.0 Hz, 6H). 13 C NMR (101 MHz, CD 3 D) δ 76.1 (d, J (C,F) = 321.7 Hz), 55.5 (d, J (C,F) = 21.2 Hz), 39.4 (d, J (C,F) = 71.3 Hz). 19 F NMR (376 MHz, CD 3 D) δ 171.3. HRMS: (ESI TF) m/z: [M+H HCl] + Calcd for C 5 H 9 FN m/z 102.0714; Found 102.0718. IR: 3021.4.2, 2774.1, 1477.3, 1335.9, 1249.9, 1085.3, 589.4 cm 1. DSC: thermal potential of 1260 J/g with an onset temperature of 224 C. mp: 160 C S6
methyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12). DCC (1.15 eq.) DMAP (8 mol%) t-buh (1.1 eq.) 8 H DCM; 0 o Ctort 16 h 12 To a solution of 3 (methoxycarbonyl)bicyclo[1.1.1]pentane 1 carboxylic acid (8) (100 mg, 0.588 mmol) in DCM (2 ml), was added DMAP (5.74 mg, 0.047 mmol, 8 mol%), followed by a 70% w/w solution of tert butylhydroperoxide in water (83.3 µl, 0.646 mmol, 1.1 eq.), and stirred at 0 C for 5 min. To this reaction mixture was added a solution of DCC (139 mg, 0.676 mmol, 1.15 eq.) in DCM (1 ml), and the resulting mixture was stirred at 0 C for 30 min. The reaction mixture was then allowed to warm to rt and stir for 16 h. The reaction mixture was evaporated and filtered through a short pad of silica gel with 20% diethyl ether in petroleum ether, followed by purification with silica gel flash chromatography (gradient elution from 0:100 to 20:80 with product 12 eluting from 10:90 to 15:85 diethyl ether petroleum ether) to afford 12 (102 mg, 72%) as a colourless solid.* *We have observed that the compound turns yellow on standing overnight in the refrigerator; however, no significant decomposition of the product was observed after prolonged storage (>30 days) under cold conditions ( 20 ºC). We have employed both freshly prepared and stored 12 as starting material in our experiments and have observed similar outcomes. 1 H NMR (400 MHz, CDCl 3 ) δ 3.70 (s, 3H), 2.38 (s, 6H), 1.32 (s, 9H). 13 C NMR (101 MHz, CDCl 3 ) δ 169.3, 166.4, 84.0, 53.4, 52.0, 38.6, 35.9, 26.2. HRMS: (ESI TF) m/z: [M+H] + Calcd for C 12 H 19 5 m/z 243.1227; Found 243.1227. (ESI TF) m/z: [M+Na] + Calcd for C 12 H 18 Na 5 m/z 265.1046; Found 265.1058. IR: 2991.2, 1766.9, 1724.6, 1367.9, 1343.2, 1263.7, 1207.2, 1104.8, 1004.2 cm 1. ethyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12a). DCC (1.15 eq.) DMAP (8 mol%) t-buh (1.1 eq.) 8a H DCM; 0 o Ctort 16 h 12a To a solution of 3 (ethoxycarbonyl)bicyclo[1.1.1]pentane 1 carboxylic acid (8a) (500 mg, 2.72 mmol) in DCM (7 ml), was added DMAP (26.5 mg, 0.217 mmol, 8 mol%), followed by a 70% w/w solution of tert butylhydroperoxide in water (384 µl, 2.98 mmol, 1.1 eq.), and stirred at 0 C for 5 min. To this reaction mixture was added a solution of DCC (644 mg, 3.12 mmol, 1.15 eq.) in DCM (6.5 ml), and the resulting mixture was stirred at 0 C for 30 min. The reaction mixture was then allowed to warm to rt and then stir for 16 h. The reaction mixture was evaporated and filtered through a short pad of silica gel with 20% diethyl ether in petroleum ether, followed by purification with S7
silica gel flash chromatography (gradient elution from 0:100 to 20:80 with product 12a eluting from 10:90 to 20:80 diethyl ether petroleum ether) to afford 12a (490 mg, 70%) as a pale yellow oil.* *No significant decomposition of the product was observed after prolonged storage (>20 days) under cold conditions ( 20 ºC). We have employed both freshly prepared and stored 12a as starting material in our experiments and have observed similar outcomes. 1 H NMR (400 MHz, CDCl 3 ) δ 4.14 (q, J = 7.1 Hz, 2H), 2.37 (s, 6H), 1.31 (s, 9H), 1.26 (t, J = 7.1 Hz, 4H). 13 C NMR (101 MHz, CDCl 3 ) δ 168.8, 166.2, 83.8, 60.8, 53.2, 38.6, 35.6, 26.1, 14.1. IR: 2981.8, 1773.1, 1733.7, 1369.2, 1269.1, 1204.8, 1022.5 cm 1. ethyl 3 phenylbicyclo[1.1.1]pentane 1 carboxylate (15). To ethyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12a) (50 mg, 0.195 mmol) was added to a sealed tube, was thoroughly flushed with argon. Benzene (1 ml) was added and the reaction mixture stirred at 110 C for 16 h. The reaction mixture was evaporated under reduced pressure and diluted with diethyl ether. The organics was washed with saturated bicarbonate, dried over sodium sulphate, filtered and concentrated in vacuo. The residue was purified by preparative TLC chromatography (8% diethyl ether in petroleum ether) to afford 15 (7 mg, 17%) as a colourless oil. The remaining aqueous layer was acidified with 6 N HCl and extracted with diethyl ether, dried over sodium sulphate, filtered and concentrated in vacuo to afford 8a (10 mg, 28%) as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 7.35 7.28 (m, 2H), 7.26 7.20 (m, 3H), 4.17 (q, J = 7.1 Hz, 2H), 2.32 (s, 6H), 1.29 (t, J = 7.1 Hz, 3H). 13 C NMR (101 MHz, CDCl 3 ) δ 170.5, 139.9, 128.4, 127.0, 126.2, 60.7, 53.5, 41.8, 37.3, 14.4. IR: 2978.6, 1729.2, 1371.2, 1296.4, 1200.2, 1112.9, 1016.7, 749.5, 697.9 cm 1. S8
1 H NMR, 13 C NMR, 19 F NMR Spectra and X ray crystal structures 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3), 1 H NMR (400 MHz, CDCl 3 ) 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3), 13 C NMR (101 MHz, CDCl 3 ) S9
3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3), 19 F NMR (376 MHz, CDCl 3 ) S10
Single X ray crystal structure of 3 fluorobicyclo[1.1.1]pentane 1 carboxylic acid (3). Bond lengths (Å). C1 2 1.2611(19) C1 1 1.2674(19) C1 C2 1.482(2) C2 C5 1.550(2) C2 C4 1.555(2) C2 C3 1.567(2) C2 C6 1.815(2) C3 C6 1.531(2) C4 C6 1.536(2) C5 C6 1.537(2) C6 F1 1.3678(18) Bond angles ( ) 2 C1 1 124.32(14) 2 C1 C2 118.51(14) 1 C1 C2 117.11(14) C1 C2 C5 128.26(15) C1 C2 C4 128.34(13) C5 C2 C4 88.81(12) C1 C2 C3 122.76(13) C5 C2 C3 88.11(12) C4 C2 C3 87.69(12) C1 C2 C6 175.97(13) C5 C2 C6 53.64(10) C4 C2 C6 53.57(9) C3 C2 C6 53.21(9) C6 C3 C2 71.71(11) C6 C4 C2 71.90(11) C6 C5 C2 72.03(11) F1 C6 C3 124.84(14) F1 C6 C4 125.68(14) C3 C6 C4 89.69(12) F1 C6 C5 125.53(14) C3 C6 C5 89.93(13) C4 C6 C5 89.99(13) F1 C6 C2 179.79(16) C3 C6 C2 55.08(9) C4 C6 C2 54.53(9) C5 C6 C2 54.33(9) S11
tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 1 H NMR (400 MHz, CDCl 3 ) tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 13 C NMR (101 MHz, CDCl 3 ) S12
tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 19 F NMR (376 MHz, CDCl 3 ) tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 1 H NMR (400 MHz, CD 3 D) S13
tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 13 C NMR (101 MHz, CD 3 D) tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13), 19 F NMR (376 MHz, CD 3 D) S14
Single X ray crystal structure of tert butyl (3 fluorobicyclo[1.1.1]pentan 1 yl)carbamate (13). Bond lengths (Å) C1 N1 1.4223(18) C1 C4A 1.532(7) C1 C2 1.536(3) C1 C3 1.540(3) C1 C4 1.552(3) C1 C2A 1.570(8) C1 C3A 1.604(7) C1 C5 1.812(2) C2 C5 1.527(3) C3 C5 1.542(3) C4 C5 1.546(3) C2A C5 1.506(8) C3A C5 1.531(7) C4A C5 1.460(8) C5 F1 1.3714(17) C6 1 1.2121(17) C6 2 1.3431(17) C6 N1 1.3485(18) C7 2 1.4785(17) C7 C9 1.508(2) C7 C8 1.514(2) C7 C10 1.520(2) C11 N2 1.4166(18) C11 C14 1.541(2) C11 C15 1.553(2) C11 C13 1.556(2) C11 C12 1.812(2) C12 F2 1.3724(17) C12 C14 1.518(2) C12 C15 1.530(2) C12 C13 1.530(2) C16 3 1.2143(17) C16 4 1.3456(17) C16 N2 1.3469(19) C17 4 1.4767(17) C17 C18 1.507(2) C17 C19 1.507(2) C17 C20 1.520(2) Bond angles ( ) N1 C1 C4A 127.1(3) N1 C1 C2 127.25(16) N1 C1 C3 128.18(15) C2 C1 C3 89.29(19) N1 C1 C4 122.84(15) C2 C1 C4 88.80(18) C3 C1 C4 88.17(17) N1 C1 C2A 126.6(3) C4A C1 C2A 87.5(4) N1 C1 C3A 130.4(3) C4A C1 C3A 85.6(4) C2A C1 C3A 85.2(4) N1 C1 C5 176.77(13) C4A C1 C5 50.9(3) C2 C1 C5 53.51(13) C3 C1 C5 54.03(12) S15
C4 C1 C5 54.04(13) C2A C1 C5 52.3(3) C3A C1 C5 52.8(3) C5 C2 C1 72.52(15) C1 C3 C5 72.01(14) C5 C4 C1 71.60(14) C5 C2A C1 72.1(4) C5 C3A C1 70.5(3) C5 C4A C1 74.5(3) F1 C5 C4A 125.3(3) F1 C5 C2A 124.5(3) C4A C5 C2A 92.6(4) F1 C5 C2 126.11(17) F1 C5 C3A 123.5(3) C4A C5 C3A 90.8(4) C2A C5 C3A 90.0(4) F1 C5 C3 126.06(16) C2 C5 C3 89.57(19) F1 C5 C4 125.55(16) C2 C5 C4 89.36(18) C3 C5 C4 88.33(18) F1 C5 C1 179.90(17) C4A C5 C1 54.6(3) C2A C5 C1 55.6(3) C2 C5 C1 53.97(13) C3A C5 C1 56.6(3) C3 C5 C1 53.95(12) C4 C5 C1 54.36(12) 1 C6 2 125.93(13) 1 C6 N1 123.90(13) 2 C6 N1 110.15(12) 2 C7 C9 108.76(12) 2 C7 C8 111.85(12) C9 C7 C8 113.87(15) 2 C7 C10 102.64(12) C9 C7 C10 110.36(14) C8 C7 C10 108.78(13) N2 C11 C14 122.94(13) N2 C11 C15 127.65(13) C14 C11 C15 88.18(12) N2 C11 C13 129.43(13) C14 C11 C13 87.80(12) C15 C11 C13 87.79(12) N2 C11 C12 175.88(13) C14 C11 C12 53.07(9) C15 C11 C12 53.39(9) C13 C11 C12 53.38(9) F2 C12 C14 125.47(14) F2 C12 C15 125.16(13) C14 C12 C15 89.90(13) F2 C12 C13 125.80(14) C14 C12 C13 89.61(13) C15 C12 C13 89.58(12) F2 C12 C11 179.49(15) C14 C12 C11 54.27(9) C15 C12 C11 54.59(9) C13 C12 C11 54.70(9) C12 C13 C11 71.91(11) C12 C14 C11 72.66(11) C12 C15 C11 72.02(10) 3 C16 4 126.01(13) 3 C16 N2 124.63(13) 4 C16 N2 109.35(12) 4 C17 C18 112.23(12) 4 C17 C19 108.51(13) C18 C17 C19 112.92(16) 4 C17 C20 101.82(12) C18 C17 C20 110.04(14) C19 C17 C20 110.77(15) C6 N1 C1 121.96(12) C16 N2 C11 122.58(12) C6 2 C7 120.81(11) C16 4 C17 121.99(11) S16
1,3 bis(3 fluorobicyclo[1.1.1]pentan 1 yl)urea (14), 1 H NMR (400 MHz, CD 3 D) 1,3 bis(3 fluorobicyclo[1.1.1]pentan 1 yl)urea (14), 13 C NMR (101 MHz, CD 3 D) S17
1,3 bis(3 fluorobicyclo[1.1.1]pentan 1 yl)urea (14), 19 F NMR (376 MHz, CD 3 D) S18
1,3 bis(3 fluorobicyclo[1.1.1]pentan 1 yl)urea (14). Bond lengths (Å) C1 1 1.235(2) C1 N1 1.3568(16) C1 N1 1.3569(16) C2 N1 1.4186(19) C2 C5A 1.525(10) C2 C4 1.533(10) C2 C3 1.536(6) C2 C4A 1.549(11) C2 C3A 1.561(7) C2 C5 1.566(8) C2 C6 1.810(2) C3 C6 1.526(7) C4 C6 1.543(11) C5 C6 1.490(9) C3A C6 1.526(7) C4A C6 1.480(12) C5A C6 1.544(10) C6 F1 1.3654(18) Bond angles ( ) 1 C1 N1 122.70(9) 1 C1 N1 122.69(9) N1 C1 N1 114.61(17) N1 C2 C5A 126.3(4) N1 C2 C4 124.1(4) N1 C2 C3 126.8(3) C4 C2 C3 87.8(4) N1 C2 C4A 126.7(5) C5A C2 C4A 86.9(5) N1 C2 C3A 127.9(3) C5A C2 C3A 88.0(4) C4A C2 C3A 87.8(4) N1 C2 C5 129.6(3) C4 C2 C5 87.1(5) S19
C3 C2 C5 88.2(4) N1 C2 C6 178.20(12) C5A C2 C6 54.3(4) C4 C2 C6 54.2(4) C3 C2 C6 53.5(3) C4A C2 C6 51.6(4) C3A C2 C6 53.2(3) C5 C2 C6 51.8(3) C6 C3 C2 72.5(3) C2 C4 C6 72.1(5) C6 C5 C2 72.6(4) C6 C3A C2 71.8(3) C6 C4A C2 73.4(5) C2 C5A C6 72.3(4) F1 C6 C4A 123.9(4) F1 C6 C5 125.1(3) F1 C6 C3A 125.5(3) C4A C6 C3A 91.7(5) F1 C6 C3 126.1(3) C5 C6 C3 91.5(4) F1 C6 C4 125.4(4) C5 C6 C4 89.6(4) C3 C6 C4 87.8(4) F1 C6 C5A 127.1(4) C4A C6 C5A 88.7(4) C3A C6 C5A 88.6(4) F1 C6 C2 179.02(14) C4A C6 C2 55.1(4) C5 C6 C2 55.6(3) C3A C6 C2 55.0(3) C3 C6 C2 54.0(2) C4 C6 C2 53.7(4) C5A C6 C2 53.4(4) C1 N1 C2 121.83(12) S20
3 fluorobicyclo[1.1.1]pentan 1 aminium chloride (2.HCl), 1 H NMR (400 MHz, CD 3 D) 3 fluorobicyclo[1.1.1]pentan 1 aminium chloride (2.HCl), 13 C NMR (101 MHz, CD 3 D) S21
3 fluorobicyclo[1.1.1]pentan 1 aminium chloride (2.HCl), 19 F NMR (376 MHz, CD 3 D) S22
methyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12), 1 H NMR (400 MHz, CDCl 3 ) methyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12), 13 C NMR (101 MHz, CDCl 3 ) S23
ethyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12a), 1 H NMR (400 MHz, CDCl 3 ) ethyl 3 ((tert butylperoxy)carbonyl)bicyclo[1.1.1]pentane 1 carboxylate (12a), 13 C NMR (101 MHz, CDCl 3 ) S24
ethyl 3 phenylbicyclo[1.1.1]pentane 1 carboxylate (15), 1 H NMR (400 MHz, CDCl 3 ) ethyl 3 phenylbicyclo[1.1.1]pentane 1 carboxylate (15), 13 C NMR (101 MHz, CDCl 3 ) S25